Callicarpa candicans (Burm. f.) Hochr. (Callicarpa cana L.) is a medicinal plant that is distributed mainly in the tropics and subtropics of Asia and finds a wide range of uses in traditional medicine. In this study, we attempted and optimized the microwave-assisted hydro-distillation (MAHD) process to obtain essential oil from the leaves of C. candicans. In addition, the obtained oil was analyzed for volatile composition by gas chromatography–mass spectrometry (GC-MS) and assayed for bioactivity against several bacteria and cancer cell lines. To optimize the extraction process, response surface methodology (RSM) in combination with central composite design (CCD) was adopted. Experimental design and optimization were carried out with respect to three experimental factors including the ratio of water to raw material, extraction time, and microwave power. The optimal extraction conditions were obtained as follows: water to raw material ratio of 6/1 (v/w), extraction time 42 min, and microwave power 440 W. Composition determination of the obtained C. candicans essential oil indicated the presence of predominant components including caryophyllene (10.45%), cadinene (10.28%), gurjunene (8.95%), muurolene (8.92%), selinene (7.06%), selinene (5.59%), and copaene (5.40%). In comparison with the essential oils obtained via traditional hydro-distillation method, the essential oil extracted by MAHD exhibited superior anti-proliferative activity on all tested cancer cell lines. Current results imply that the MAHD is capable of recovering biologically-active natural products of greater quantity than that recovered by the conventional distillation.

The results of in silico screening of the 50 isolated compounds from Millettia dielsiana against the target proteins PDE4 (PDE4A, PDE4B, and PDE4D) showed binding affinity ranges from −5.81 to −11.56, −5.27 to −13.01, and −5.80 to −12.12 kcal mol⁻¹, respectively, with median values of −8.83, −8.84, and −8.645 kcal mol⁻¹, respectively. Among these compounds, Millesianin F was identified as the most promising PDE4A inhibitor due to its strongest binding affinity with the target protein PDE4A. (−11.56 kcal mol⁻¹). This was followed by the compound 5,7,4′-trihydroxyisoflavone 7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (D50) with the binding affinity value of −11.35 kcal mol⁻¹. For the target protein PDE4B, compound D50 exhibited the strongest binding affinity value of −13.01 kcal mol⁻¹, while showing poorer inhibition ability for PDE4D. The 100 ns MD simulation examination (radius of gyration, Solvent Accessible Surface Area (SASA), Root-Mean-Square Deviation (RMSD), Root-Mean-Square Fluctuation (RMSF), and hydrogen bonding) was carried out to examine the overall stability and binding efficiency of the protein–ligand complex between compounds (Millesianin F, Millesianin G, Claclrastin-7-O-β-d-glucopyranoside, 7-hydroxy-4′,6 dimethoxyisoflavone-7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside, 7-hydroxy-4′,8-dimethoxyisoflavone 7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside, Odoratin-7-O-β-d-glucopyranoside, and 5,7,4′-trihydroxyisoflavone 7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside) and PDE4 (A, B) subtype proteins. Compound D50 has shown strong anti-inflammatory activity, as evidenced by experimental results. It effectively inhibits PDE4B and PDE4D, with IC₅₀ values of 6.56 ± 0.7 µM and 11.74 ± 1.3 µM, respectively. Additionally, it reduces NO production, with an IC₅₀ value of 5.40 ± 0.9 µM. Based on these findings, it is promising and considered a potential novel anti-inflammatory drug for future development.

In silico docking studies of 50 selected compounds from Millettia dielsiana Harms ex Diels (family Leguminosae) were docked into the binding pocket of the PI3K/mTOR protein. In there, compounds trans−3−O-p-hydroxycinnamoyl ursolic acid (1) and 5,7,4′−trihydroxyisoflavone 7−O−β−D−apiofuranosyl−(1→6)−β−D−glucopyranoside (2) are predicted to be very promising inhibitors against PI3K/mTOR. They direct their cytotoxic activity against Hepatocellular carcinoma with binding affinity (BA) values, the pulling work spent to the co-crystallized ligand from the binding site of PI3K/mTOR (W and F_max), and the non-equilibrium binding free energy (∆G_neq^Jar) as BA values = −9.237 and −9.083 kcal/mol, W = 83.5 ± 10.6 kcal/mol with F_max = 336.2 ± 45.3 pN and 126.6 ± 21.7 kcal/mol with F_max = 430.3 ± 84.0 pN, and ∆G_neq^Jar = −69.86074 and −101.2317 kcal/mol, respectively. In molecular dynamic simulation, the RMSD value of the PI3K/mTOR complex with compounds (1 and 2) was in the range of 0.3 nm to the end of the simulation. Therefore, the compounds (1 and 2) are predicted to be very promising inhibitors against PI3K/mTOR. The crude extract, ethyl acetate fraction and compounds (1 and 2) from Millettia dielsiana exhibited moderate to potent in vitro cytotoxicity on Hepatocellular carcinoma cell line with IC₅₀ values of 81.2 µg/mL, 60.4 µg/mL, 23.1 μM, and 16.3 μM, respectively, and showed relatively potent to potent in vitro antioxidant activity on mouse hepatocytes with ED₅₀ values of 24.4 µg/mL, 19.3 µg/mL, 30.7 μM, and 20.5 μM, respectively. In conclusion, Millettia dielsiana and compounds (1 and 2) are predicted to have very promising cytotoxic activity against Hepatocellular carcinoma and have a hepatoprotective effect.

From the essential oil of the whole plant from Elsholtzia ciliata, obtained by hydrodistillation and then using gas chromatography/mass spectrometry to analyze and identify 42 constituents, carveol (26.89%) and z-citral (29.35%) main contents (collected in the dry season time); and 46 constituents, cis-ocimene (17.95%), carveol (14.84%), Z-citral (17.01%), isocaryophyllene (13.19%) and trans-caryophyllene (9.76%) as main contents (collected in the rainy season time). The major essential oils in dry season exhibited good inhibition activity on the Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Candida albicans with MIC value of 200 μg/mL; exhibited weak cytotoxic activity on the PC-3 line (IC50 66.34 μg/mL) and A549 line (IC50 93.11 μg/mL). The essential oils in rainy season exhibited good inhibition activity on the Escherichia coli, Bacillus subtillis and Saccharomyces cerevisiae with MIC value of 200 μg/mL and Candida albicans with MIC value of 100 μg/mL; displayed good cytotoxic activity on the PC-3 line (IC50 30.62 μg/mL) and Hep-G2 line (IC50 22.78 μg/mL), however have weak cytotoxic activity on the A549 line (IC50 85.35 μg/mL).